Grinding-machine.



B. SWEET GRINDING MACHINE. APPLiCATlON FILED OCT. 23. 1915.

1, 173,225, Patented Feb. 29, 1916.

27 2 SHEETSSHEET I- 1? 28 A 5 I JIZUW @IM Maw/60f THE COLUMBIA PLANOGRAPH co., WASHINGTON. D. c.

B. SWEET.

GRINDING MACHINE. APPLICATION man OCT. 23. 1915.

1,173,225. Patented Feb. 29, 1916. 2 SHEETS-SHEET 2- nnrrnn s'ra rns Parana oration.

BYRON SWEEQnOF' POPLAR GROVE, ILLINOIS.

enr nnrne-ivmcninn.

Application-filed October 23, 1 915.

Tovall whom it may concern: 7

Be it known that I, BYRON SWEET, a citizenof 111118 United States, residing at Poplar Grove, in the county of Boone and Stateof Illinois, have invented certainnew and useful Improvements in Grinding-Machines, of which the following is specification.

This invention relates in general ,to grinding machines and has more particular .referenceto those especiallyadapted for sharpening mower and reaper cutting knives .or sickles.

.Griding machines of this character have been in most instances so constructed that the grinding wheel when in operation is antomatically moved backand .forth over the surfaces being ground. VGenerally, in such machines a cone-facedgrinding wheel ,isemployed, adapted to simultaneously sharpen the edges of two adjoining knife sections. Usage of a cutter bar develops irregularities in the cuttingedge of ,its sections, and repeated sharpening with a vcone faced grinding wheel results in a somewhat concave cutting edge. dVhen a, grinding machine of this type and in which the grinding wheel is automatically oscillated in a fixed path is employedforsharpening a cutter'bar having such irregularities in the cutting edges, theseedges are not properlysharpened, since the .controlof the wheel is not such as iwillpermit proper adaptation-tothe peculiarities of each cuttingledge.

The primary object of my invention is to provide a grinding machine for sharpening mower and reaper knives in which the grinding wheel shall be under immediate, direct manual control-of the operator, so that he may position and apply the wheel to the knife sections in the proper relationxto obtain perfect sharpening of the edges aregardless of irregularlties therein.

My invention also contemplates the provision of a grindingmachine which, while adapted to sharpen butone edge ofva section at one time, may be applied to the edge of the, next adjoining. section without changing or adjusting the position of thesickle, by simply oscillating the grinding wheel .so as to dispose'itsgrinding face at the angleof the said adjacent edge. This adjustment maybe attained instantaneously, since the grinding wheel is under direct manna-Loontrol of theoperator.

Anotherobject of my inventionis, to provide a; grinding machine of. the character de- Specification'of Letters Patent.

Patented Feb. 29, 1916.

Serial No. 57,429.

scribed of simple and improved construction, which may be cheaply manufactured proved grinding machine, showing the same in vnorrnal inoperative position; Fig. 2 is a plan view thereof; Fig. 3 is an enlarged vertical'sectional view through the machine takenon the line33 of Fig. 2, showing one position of-the grinding wheel when in op eration; Fig. 4 is a vertical sectional view taken on the line el-d of Fig. 3; Fig. 5 is a plan .view of a portion of a sickle shown as disposed directly below'the grinding wheel; Fig. 6 is a cross sectional view through the grinding head taken onthe line 6-6 of Fig. 1;.and Fig. 7 is a detail view in perspective of a bearing block employed in the mounting of the grinding wheel.

Referring to the drawings, it will be observed that a frame suitable for supporting the several working elements employed in my grinding machine, comprises legs 8, spaced apart by upper and lower side bars 9 and 11 respectively, and by cross bars 12, 13, 14, and15. The cross bar 15, theends of whicheXtend beyond the side of the frame constitutes with the brackets 16 secured thereto, a work support adapted to receive a cutting knife or sickle such as is employed in mowers and reapers. The sections of the sickle rest upon the top face of the bar 15 and the rib or backing thereof is engaged by the bracket 16 and held against lateral displacement while permitting the sickle to be freely adjusted lengthwise thereon. The work supporting bar 15 is recessed at10 so as to provide clearance for the grinding wheel adapted to be employed in sharpening a knife positioned on the work support.

Means for supporting and guiding the grinding wheel 17 into and out of operative relation with the rest 15 comprises a pivoted frame and a holder designated in general by reference characters 18 and 19 respectively. The frame 18 triangular in shape asshown in Fig. 2, ispivoted at one endonthe ends of a shaft21 mounted fixedly on uprigl1t posts22 and 23 which are interposed between and securedito the cross bars 13 and 14. These posts are formed with a slot extending to the shaft aperture so that a bolt 25 passed through the split sections of the post may be tightened to clamp the post to the shaft 21. The post 23 constantly urging the said frame upwardly.

A grooved pulley 27 and a pulley 28 of smaller diameter rigidly secured thereto are rotatably mounted on the shaft 21 between the posts 22 and 23. The pivoted support 1.8 is provided with an extensible end upon which the grinding wheel 17 is journaled. This extensible end is so mounted as to turn on an axis intersecting that of the grinding wheel at right angles so that the grinding wheel may not only be moved toward and away from the support 18 but oscillated laterally with respect thereto. In the present instance, I have illustrated this end structure in the form of a pipe section 29 slidably and rotatably mounted in spaced cross pieces 31 and 32 of the support 18, the outer end of the pipe section being split and shaped to provide a forked end between the arms 33 of which is mounted the grinding wheel. Referring to Fig. 6, it will be noted that the grinding wheel 17 of a flat faced type and a grooved pulley 30 are clamped fixedly together on an arbor or spindle 34 by nuts 35, the reduced ends 36 of which are journaled in blocks 37. These blocks, preferably of wood, are shaped on their outer sides with ribs 38 fitting in the channels of the pipe section arms 33, the blocks being fixedly secured thereto by bolts 39. To facilitate assembling the grinding wheel head and obtain simplicity in construction, the bearing blocks are formed with oblique slots 41 leading to the bearing aperture therethrough whereby the ends 36 of the arbor 34 may be quickly and easily positioned in the blocks after the grinding wheel and pulley have been secured to the arbor, rods 42 passing lengthwise through the blocks being employed to hold the arbor against withdrawal from the slots. These bolts secured in position by nuts at the ends of the blocks are extended forwardly so as to afford a support for a handle 43 which is bolted to the rods as is shown clearly in Fig. 3. Driving connection between the pulleys 27 and 30 is established by means of a coiled wire spring belt 44.

From the foregoing, it will be apparent that without disturbing the driving connection between the grinding wheel and drive pulley an operator grasping the handle 43 may raise and lower the grinding wheel in an arcuate path about the pivot axis of the support 18, draw the wheel backwardly and forwardly by reason of the slidable mount ing of the forked holder 19,and oscillate the wheel laterally on the longitudinal axis of the said. holder. 1

Foot-operated means are provided for moving the grinding wheel back and'forth over the work support so that an operator seated in front of the machine may control the angle and depth of grinding by hand and effect the back and forth feedingmovement by foot operation. The foot-operated means comprises a lever 45 pivoted intermediate its ends at 46 on a block 47 centrally fixed to the cross bar 12, theupper end of the lever being formed to provide a yoke 48 passing over the rod 29 and the lower end being provided with laterally. projecting,

foot rests 49. By swinging the lower end of the lever 45 backwardly its upper yoked end 48 will be swung forwardly into engage ment with a laterally projecting pin 5l-on the rod 29 so as tomove the grinding wheel head forwardly or outwardly on the frame 18, such movement being against the resistance of the spring belt 44. A stop 52 on by abut the inner end of the rod 29 limits, t1ng against cross piece '32, the. outward movement of the grinding wheel head;

lVhen the operator releases his hold on the grinding wheel head in the position shown in Fig. 3, the spring 26 will raise the wheel supporting frame 18 tonormal inoperative position shown in Fig. 1, determined by abutment of the rod 29 against the closed outer end of the yoke 48.

In operating the grinding machine, the pulley 28 being driven by a belt from a suit able source of power, a knife is'positioned on the support 15 so that two adjoining knife sections thereof are disposed over the clearance recess 10, in the manner shown in Fig. 5. An operator seated-in front of the machine with his feet on the rests 49 and grasping the handle 43 is then ready to commence the sharpening operation. The grinding wheel head will be lowered by hand and advanced toward the cutter bar by pushing backwardly on the foot rest until thegrinding wheel with its axis of rotation horizontally disposed, is positioned centrally interl mediate the teeth A and B.

To sharpen the edge A the operatorc'ants the grinding 7 wheel to the right by hand until the face thereof assumes an angle corresponding to the bevel of the cutting edge. 'Theffoot lever is then operated to advance the cuttmg wheel, the path of the wheel, the angle of its face and determined and controlled by" hand. In sharpening the face A, the cuttingface of the wheel having been properly angled will travel in the path indicated by dotted lines 52, Fig. 5, it being apparent that during the advancing of the wheel along the cutting edge, the operator may control to a.

the depth of grinding being ni'cety the depth and angleof grinding, and that'should the cutting edge contain irregularities or notches, these :may :be .properly ground by correct manipulation :of the grinding wheel throughithe'han'dl'e .43. To grind the edge B" ofthe adjoining knife, the grinding wheel is canted in the opposite direction so that the angle of its face corresponds to the bevel of the cutting edge of thisknife, and since the wheel will not quite contact the said cuttingedge afterbeing canted, the sickle should be moved lengthwise to the left until in proper relation to the wheel, which is then worked back and forth in the manner previously described until this edge has been sufliciently ground. Should the operator, after having finished grinding an edge of a knife section, or at any time, releases his grasp on the handle t3, the grinding head will be instantly raised 'to inoperative position by'the spring 26 and held in such position by the yoke 48. As will be apparent, to sharpen the remaining sections of theknife, the same may be adjusted lengthwise to position the next adjacent cutting edges over the clearance recess 10 and the grinding operations above grin ding described repeated.

With my improved grinding machine, a sickle may be very satisfactorily sharpened in a short period of time and with each cutting edge properly ground throughout its entire length; It will be noted that the important and delicate operations of guiding the grinding wheel at the proper angle anddetermining the depth of grinding is controlled by hand and that the operation of feeding the grinding wheel back and forth is effected by foot control. Thus, the more delicate hand control is re lieved of that operation, the feeding, which requires force rather than precision in guiding the grinding wheel. It will also be noted that the particular construction of the several parts constituting my improvements are such that, if necessary, they may be replaced very easily, since the construction is exceedingly simple and requires practically no machine work in making the several parts.

From the foregoing it is believed that my invention and the principles of operation involved will be readily understood, and it should be apparent that various changes in details of construction might be resorted to without departing from the invention or sacrificing any of its material advantages.

I claim:

1. In a grinding machine, the combination of a drive pulley, a swinging frame coaxially mounted with the drive pulley, a wheel, means slidably mounted upon and movable longitudinally of said frame and supporting the grinding wheel adjacent to the outer end of the frame, and

a contractile spring belt connecting the drivepulley and grinding wheel.

2. In agrindingjmaChine, the combination 'ofa supporting frame provided at itsfront end-"with awork support, aaswinging frame pivoted on a horizontal axis to the rear por tion of the supporting frame and extending forwardly toward said work support, a grinding wheel, means so sliclably support ing the grinding wheel on the pivoted frame that the grinding wheelmay be reciprocably moved longitudinally thereon so as to be capable of back and forth feed movement relative to the work support, hand operable means in connection with the grinding wheel whereby the same may be swung by hand on the pivot axis of said swinging frame toward and away from the work support, 'means for rotating the grinding wheel, and means for reciprocating said grinding wheel supporting means on said swinging frame.

3. In a grinding machine, the combination of means for supporting a sickle, a grinding wheel, a frame pivoted at one end and sup porting the grinding wheel at its outer end over the sickle and so that the grinding wheel may be oscillated laterally and moved back and forth over the work support relatively to the pivot axis of said supporting frame and swung toward and away from said support on the said pivot axis as a fulcrum, a pulley concentric with the pivot axis of said supporting frame, and a contractile spring belt driving connection between the grinding wheel and said pulley whereby the grinding wheel will be con stantly urged toward the said pivot axis and forth between and with respect to its driving pulley and the work support and oscillated on an axis substantially intersecting that of the grinding wheel at right angles, said spring belt constantly urging the grinding wheel toward said driving pulley and handle means connected with the grinding wheel whereby an operator may by direct manual control of the grinding wheel position it at an angle with respect to work on the work support and move the wheel back and forth in the grinding operation, in which latter movement the grinding wheel is moved away from the said driving pulley against the tension of said spring belt.

5. In a grinding machine, the combination of a work support and a driving pulley spaced apart in fixed relation, a grinding wheel, a holder therefor carrying the grinding wheel normally disposed intermediate the work support and pulley, and a contrattile spring belt connection between the pulley and grinding wheel for rotating the lat er, said grinding wheel holder being so co structed that the grinding wheel may be moved back and forth over the work supportand oscillated on an axis substantially intersecting that of the wheel at right angles, the said holder being movable over the work support away from the driving pulley against the tension of said spring. and consequently, being constantly urged toward the driving wheel by said spring.

6. In a grinding machine, the combination of a work support and a driving pulley mounted in fixed spaced relation, a frame pivoted coaxially with thedriving pulley and extending therefrom toward the work support, a grinding wheel, means movably securing the grinding wheel to said frame so that the grinding wheel may be moved longitudinally of the said frame whereby the proximity of the grinding Wheel to the work support may be varied by swinging said frame on its pivot and the grinding wheel may be moved longitudinally upon and with respect to said frame so as to be moved back and forth relatively to the work support, and a contractile spring belt connecting the driving pulley and grinding wheel whereby the latter is driven and is capable of said back and forth movement and whereby also the spring constantly urges the grinding wheel toward the driving pulley.

7 A grinding machine, comprising a frame, a work support and a grinding wheel support mounted thereon spaced apart horizontally. in fixed relation, the grinding wheel support being pivoted on a horizontal axis at its end farthest from the work support, a driving pulley co-axial with the pivot axis of the wheel support, a grinding wheel, a holder therefor so mounted on the wheel support as to be movable lengthwise lever pivoted on the frame beneath the wheel support, connectedat its upper end with the wheel holder, and beingoperable so as to move the wheel holder lengthwise to move the grinding wheelback and forth over work positioned on the Work holder.

8. A grinding machine, comprising frame, a horizontally disposed support pivoted at one end on the frame on a horizontal axis, a grinding wheel, a holder upon which the grinding wheel is journaled on a horizontally disposed axis, the holder being so slidably and rotatably mounted on the outer end of said support that it may he slid horizontally lengthwise ofthe support and turned on a horizontal axis intersecting the wheel, a pulley fixedly connected with the grinding wheel, a pulley, mounted on the pivot axis of said support, a spring belt connection between the said pulley constantly urging the wheel holder to an innermost position on the support, a work support mounted on the frame beneath and at the outer end of the wheel holder, means constantly urging the outer end of the wheel support upwardly, and controlling means operable to move the grinding wheel into grinding relation with work on the work support and to move the wheel backwardly it laterally on its holder axis.

and forwardly over said work and to turn 9. In a grinding machine, the combination with a work support and a drive pulley spaced apart in fixedrelation, of a swing ing frame coaxially mounted with said drive pulley. and extending therefrom toward the work support, a grinding wheel, means supporting the grinding wheel on the outer end of said frame and being movable longitudinally upon and with respect thereto, and a contractile spring belt connecting the drive pulley and grinding wheel.

BYRON SWEET.

Copies of this patent may be obtained for five cents each, by addressing the Qommissioner of Patents, Washington, D. C. 

